S. alutacea and S. rubiginosa are sometimes difficult to separate, especially females. A case can be made for calling them the same species, and some authors do so. S. rubiginosa is usually colored much like this (averaging a bit more rusty, but highly varied in hue), but most often with spots on the tegmina (front wings) that are a bit darker than the general color. It sometimes has a pale stripe down the back, but most often not. S. alutacea, most often has a pale yellowish stripe down the middle (faint on this one), and black dots along the edges of the hind femora (the fat part of the hind legs), and it is commonly a bit yellowish, greenish, or quite green.

Follow-up comment. - The male from the same place (almost certainly the same species) has a bit of an intermediate look too, but it favors S. alutacea more in appearance, which tends to swing the pendulum in favor of that name.

I'm going to place these with S. alutacea for now, since I'm fairly certain this is what they are.